Developing device and process unit and image forming apparatus incorporating same

摘要

A developing device includes a toner bearer including a surface in which multiple recesses having a cross-sectional void rate of 50% or smaller are formed, a toner supply member to supply toner to the toner bearer, and a developer regulator disposed facing or in contact with the toner bearer and including a bent tip portion. The toner bearer has a surface roughness Ra within a range from 1.0 μm to 2.0 μm, and a surface area ratio within a range from 2.0 to 4.0. The developing device uses polymerized toner having a weight average particle diameter of 8.0 μm or smaller and an average circularity of 0.98 or greater.

主权项

1. A developing device comprising:
a toner bearer including a surface in which multiple recesses having a cross-sectional void rate of 50% or smaller are formed, the toner bearer having a surface roughness Ra within a range from 1.0 μm to 2.0 μm and a surface area ratio within a range from 2.0 to 4.0; a toner supply member to supply toner to the toner bearer; and a developer regulator disposed facing or in contact with the toner bearer to adjust a layer thickness of toner carried on the toner bearer, the developer regulator including a bent tip portion, wherein the toner is polymerized toner having a weight average particle diameter of 8.0 μm or smaller and an average circularity of 0.98 or greater.